Because you are integrated into the world created by ACGN, you are familiar with that world view. When the ending is over, you have to wave goodbye to the world, so you won't give up. Your favorite character will not appear in other stories, so you will be sad because of the ending, just like parting from your best friend. All good things must come to an end. All stories have endings. Just like our life will come to an end one day. I like Conan's world. If Conan ends one day, I will be sad and feel empty. So I am looking forward to it. It would be great if Conan could finish it a week before I die.